ranitidine vs gastric antacid

ranitidine and gastric antacid both are nouns.

Word	Noun	Adjective	Verb	Adverb
ranitidine	Yes	No	No	No
gastric antacid	Yes	No	No	No

As nouns, gastric antacid is a hypernym of ranitidine; that is, gastric antacid is a word with a broader meaning than ranitidine:

ranitidine: a histamine blocker and antacid (trade name Zantac) used to treat peptic ulcers and gastritis and esophageal reflux
gastric antacid: an agent that counteracts or neutralizes acidity (especially in the stomach)

Other hypernyms of ranitidine include histamine blocker, alkaliser, alkalizer, antacid, antiacid.

ranitidine (noun)	gastric antacid (noun)
a histamine blocker and antacid (trade name Zantac) used to treat peptic ulcers and gastritis and esophageal reflux	an agent that counteracts or neutralizes acidity (especially in the stomach)